Visibility of flicker in television pictures

Abstract

A PRIME requirement in a television system is that the flicker inherently associated with the displayed picture should be minimal. The visibility of such flicker is generally considered to depend primarily on the picture luminance, the angle subtended by the picture and the field repetition frequency. The field frequency should therefore be chosen to be close to, and ideally higher than, the fusion frequency for the human visual system. With the display luminances generally encountered in normal broadcast television, field frequency flicker is negligible in countries using 60 fields s⁻¹, and, though often noticeable, has proved acceptable in those using 50 fields s⁻¹.